An autopsy completed Monday has not been able to conclude what caused Winehouse to die. The police say that further toxicology tests are needed to establish a cause of death and should take two to four weeks to be processed.

A private funeral will be held on July 26 for friends and family.

The body of the 27-year-old "Rehab" singer was discovered by a security guard around 4 p.m. on Saturday, at which time she may have been dead for six hours, the magazine reports.

Despite reports that Amy Winehouse may have been under the influence of alcohol and drugs before she was found dead on Saturday, police found neither drugs nor drug paraphernalia anywhere in her London home, according to People.

Chris Goodman, a friend and spokesperson for Winehouse, later said that people close to her were still confused about the details of her death.

"She was in her bedroom after saying she wanted to sleep, and when he went to wake her he found she wasn't breathing," Goodman told TMZ. “He called the emergency services straight away. He was very shocked. At this stage no one knows how she died. She died alone in bed."

Winehouse had reportedly been under the care of a physician as recently as Friday, and was receiving regular check-ups due to her "fragile health."

In the meantime, the singer's parents arrived outside her home Monday, where they stood by a fan-erected memorial shrine to mourn their loss.

"I can't tell you what this means to us. It really is making this a lot easier for us," her father, Mitch Winehouse, told Us Magazine upon seeing how many fans had flocked to his daughter's home. "We're devastated and I'm speechless, but thanks for coming."